Quick releasable buckle for safety belts



June 21, 1955 F. L. DAVIS QUICK RELEASABLE BUCKLE FOR SAFETY BELTS Filed Feb. 28, 1952 INVENTOR. flaw/1w Z. flay/.5-

United States Patent Ofiice 2,710,999 Patented June 21, 1955 QUICK RELEASABLE BUCKLE FOR SAFETY BELTS Frank L. Davis, College Point, N. Y., assignor to Davis Aircraft Products Inc., New York, N. Y., a corporation of New York Application February 28, 1952, Serial No. 273,799

2 Claims. (Cl. 24-197) The invention disclosed in this patent relates to buckles of the type used on the seat belts provided on aircraft.

Objects of the invention are to provide a construction which can be readily adjusted to suit the occupant of the seat and which, independently of such adjusting means, will be quickly releasable to instantly free the occupant.

Special objects of the invention are to provide this construction in a simple, practical form which can be produced at low cost and which while small in size and light in weight, will have all the strength required for safety holding purposes.

Other special objects of the invention are to provide a buckle oi the character indicated which will be readily understandable by one unfamiliar with the structure, easy to operate either for adjustment or for quick release purposes and which in addition to its mechanical advantages, will be neat and attractive in appearance.

Other desirable objects attained by the invention and the novel features of construction, combination and relation of parts constituting the invention are set forth or will appear in the course of the following specification.

The drawing accompanying and forming part of the specification illustrates a present commercial embodiment of the invention. Structure, however, may be modified and changed as regards this illustration, all within the true intent and scope of the invention as hereinafter defined and claimed.

Fig. 1 in the drawing is a broken and part longitudinal sectional view of the buckle as used on a safety belt and showing it in the length adjusted, closed condition;

Fig. 2 is a broken part sectional plan view of the same;

Fig. 3 is a broken sectional view showing the buckle released;

Fig. 4 is an enlarged broken side elevation of the buckle in the closed condition;

Fig. 5 is a broken longitudinal sectional detail showing the bar for lengthening the strap drawn out of its socket in the end of the buckle body, this view being taken as on substantially the plane of line 55 of Fig. 2;

Fig. 6 is a cross sectional view of the quick release end of the buckle on substantially the plane of line 66 of Fig. 1.

In the present illustrated embodiment of the invention the buckle is used for connecting the adjoining ends of two belt straps 7 and 8 which at their far ends are secured by anchorage brackets 9 and It) to opposite sides of a seat in an aircraft.

The buckle is shown as made up of a channel form body 11 having freely operable take-up means at one end for holding the strap 8, and a normally closed but instantly releasable dog or pawl at the opposite end for securing the strap 7.

The adjustable take-up for strap 8 is shown as consisting of a pull bar 12 riveted or otherwise firmly secured across between the parallel sides or flanges 13 of the channel shaped base, a second, strap deflecting bar 14 similarly mounted but located nearer the end of the base and a movable loop holding bar 15 adapted normally to seat in notches 16 in the ends of the side flanges but free to be separated from the base, as in Fig. 5, for belt lengthening purposes.

The movable loop holding bar 15 is shown as carrying an angularly offset guide loop 17 embracing the strap to retain the parts in the relation shown.

The reeving of the strap, which may be webbing, is shown in Figs. 1, 3 and 5 and involves the doubling of the strap to provide an end loop 18 engaged about the movable loop carrier bar 15, the upper and lower runs of this loop extending above and below the fixed deflector bar 14 and both runs wrapped about the fixed anchorage or pull bar 12, at 19, and extending over the single final loop 18, out through the retainer loop 17.

This brings the free end of the strap into parallel relation over the attached portion of strap 8, and for adjustment purposes this free end portion is shown as carrying a cross pin 20 which can be conveniently grasped in the fingers. I

Belt tightening and slack take-up can be effected by simply pulling the handle end portion 20 of strap 8 away from the end of the buckle, as indicated by the arrow in Fig. 3. This has the effect of pulling the inner loop of strap on fixed bar 12 and the single loop of strap about the movable bar 15 until tension of the outer loop at 19, which is directly connected with the seat anchorage 10, puts enough tension on the inner loop at 19 to halt such adjustment.

Any load on the lower, anchored reach of the strap 8 causes the outer loop at 19, Fig. 3, to grip the inner loop 21 and to frictionally lock it because of these two reaches working in opposite directions, through the reversal of pull by looping the strap at 18 over the movable bar 15.

To lengthen the belt, that is, increase the extent of strap between seat anchorage 10 and the body of the buckle, the movable loop carrier bar 15 is drawn back or away from the end of the buckle body, as shown in Fig. 5, to pull the upper run 8a inward the buckle and in looped formation about the fixed cross bar 12 and movable bar 15. In this action the smaller cross bar 14 holds the single loop about the movable bar 15 spread open to reduce friction and permit easy lengthening of the strap.

After drawing in the free end of the strap, as shown in Fig. 5, the buckle body may be pulled away from the anchored end of the strap, that is toward the left in Fig. 5, to place the excess length so gained in the anchored stretch of strap and to return the movable loop carrier bar 15 back into its supported position in the notches 16 in the end of the buckle body.

After adjustment, the strap looped about the movable bar 15 will hold it in supported relation in the end of the buckle body, as shown in Figs. 1 to 4, and any tension on the belt strap will have the effect of securing it all the more firmly in that relation.

The opposite anchored strap 7 is removably connected with the buckle body by having a plate 22 secured to the free end of the same and which is provided with a projecting tongue portion 23 of a width to enter between the side flanges of the buckle body and having an opening 24 therein to receive the abruptly shouldered locking dog or lug extension 25 of a spring cam 26 pivoted between the sides of the buckle body.

The pivot for the locking cam is shown as a bolt 27 having a hexagonal or other angularly shaped head 28, non-rotatably held in a correspondingly shaped opening 29 in one side wall, this bolt extending out through the opposite side wall and there held against withdrawal by a cotter-pin, snap ring or other such suitable fastening 30.

A coiled spring 31 is shown in Fig. 2 as engaged about the bolt and freely received in a cavity 32 in the end of the cam with its opposite ends extended at 33 and 34 and engaged in seats or notches provided therefor at 35 and 36 in the cam and in the head of the bolt, respectively.

With this construction the cam may be spring tensioned in the closed, holding direction'shown in Figs. 1 and 2, by turning the bolt while partly withdrawn to free the head 28 from the holding seat 29, and the bolt then be secured to maintain this spring tension by shifting it inwardly to carry the angular head into held engagement in the angular seat, as in Fig. 2. The parts may then be locked in this spring tensioned relation by applying the fastening 30 which secures the bolt in its angularly held position.

Figs. 1 and 3 show that the cam 26 is proportioned. to admit the plate 22 and to hold it down over the flat back or base wall 37 of the buckle, with the dependent lug portion 25 which forms the holding dog firmly engaged back of the bar 38 at the forward end of the tongue 23. The upper edge of this locking bar may be rounded as indicated at 39, Fig. 3, the opposing face of the cam may be inclined toward the fiat back wall of the channel indicated in Fig. l, to enable the plate to operate as a wedge for lifting and rocking the holding dog in the opening or releasing direction.

To enable instant, free release of the holding dog, a hand lever 40 is shown secured by rivets or other fastenings 41 over the top of the cam, and this releasing lever is utilized as a cover and protective guard for the parts located between the sides of the base by extending it laterally, as shown in Figs. 2 and 6, to practically close in the space between the upper edges of the side flanges.

At its free end the releasing handle 40 may be upwardly curved, as shown at 42 in Fig. 4, for convenient, quick grasp by the fingers.

The combination cam and locking dog is of a shape which may be extruded or machined in long lengths and then cut off in short pieces to fit between the flanges of the buckle frame.

The leverage of the handle 40 is sufficient to enable release of the dog 25 from the end plate 2?. with even a light pull, and the tension of the spring is sufiicient to hold the dog closed against any accidental or unintentional release.

The release or opening of the buckle does not atiect any adjustments made for belt tightening or belt loosening purposes, so that the quick release can be utilized without losing the advantage of belt adjustments previously made.

After release, the parts may be again connected by simply forcing the end plate 22 into the end of the buckle beneath the locking dog which, under such pressure, will open and then automatically snap closed into holding engagement with the plate.

The parts are of simple, sturdy design and can be produced at reasonably low cost. The buckle is small in size and light in weight so as not to be objectionable to or in the way of the seat occupant.

The two sections of webbing are shown as having stitched or otherwise secured loops 43 at the ends of the same, and all end connections are removable so that the webbing can be completely reeved without any stitching. This is a great advantage, enabling webbing to be quickly replaced at any time without having to return the parts to the manufacturing plant.

In the illustration the loops 43 of strap 7 are caught at the ends by removable bolts 44 and 45 attached to anchorage plate 9 and the releasable keeper or catch plate 22, respectively.

The loop 43 at the outer end of strap 8 is shown held to anchorage plate 10 by a removable bolt 46 and the handle forming pin 20 which is engaged in the loop at the opposite end of this strap, is shown as a removable 4 bolt having a snap ring fastening 47 for releasably holding it in place in the strap loop.

Instead of providing a pin 20 as a pull handle for this strap, the end of the strap may be made into a plastic tip form of handle, wide enough not to slip back through the buckle.

To prevent the upper run between the fixed and movable bars 12 and 15, Fig. 5, from ballooning up when the bar 15 is pulled back into notch 16, a confining guide bar 48 may be extended across between the upper side edges of the channel base. This bar, by confining the webbing, operates to assist the webbing in guiding the loose bar 15 back into seated relation in notches 16.

The second fixed bar, 14, separates the two runs of the loop 18 extending about the movable bar 15 and deflects and wraps the lower run more fully about the first fixed pin 12, so that as the loose bar 15 is drawn outward as in Fig. 5, the fixed bars 12, 14, will cooperate with a clutching or braking cfiect to put the pull on the free end portion Ba of the web, so as to take this in and add length to the attached anchored portion of the strap.

While shown in use for safety belts, the invention may be applied to other forms of belts and harness such as the belts and harnesses used with parachutes and for snoulder harnesses and the like.

What is claimed is:

1. A buckle for adjustably holding a strap and comprising a channel form base having spaced sides with aligned notches in one end of the same, a guide bar fixed to and extending across between the sides at a point adjoining the notches in the end of the base, an anchor bar fixed to and extending across between the sides at a point inward in the base from said guide bar, a movable bar removably engageable in said notches, a strap doubled intermediate its ends into a loop and said loop engaged about said movable bar with opposite runs of said strap extending from said loop inwardly of the base past opposite sides of the guide bar and both runs doubled about said anchor bar and extended back past said guide bar and movable bar out beyond the notched end of the base and a guide loop on the movable bar embracing both the runs of the strap which extend out beyond the notched end of the base.

2. A buckle for adjustably holding a strap and comprising a channel form base having spaced sides with aligned notches in one end of the same, a guide bar fixed to and extending across between the sides at a point adjoining the notches in the end of the base, an anchor bar fixed to and extending across between the sides at a point inward in the base from said guide bar, a movable bar removably engageable in said notches, a strap doubled intermediate its ends into a loop and said loop engaged about said movable bar with opposite runs of said strap extending from said loop inwardly of the base past opposite sides of the guide bar and both runs doubled about said anchor bar and extended back past said guide bar and movable bar out beyond the notched end of the base, a guide loop on the movable bar embracing both the runs of the strap which cxtend out beyond the notched end of the base and a second guide bar fixed to and extending between the sides of the base and overlying the loop about the movable bar at a point closely adjoining the notches in the end of the base.

References Cited in the file of this patent UNITED STATES PATENTS 1,447,967 Davis Mar. 13, 1923 1,455,545 Monahan May 15, 1923 2,429,926 Davis Oct. 28, 1947 

